Electrical switch



May 5, 1925.

j 1,536,295 c. L. HOPKINS ET AL ELECTRICAL SWITCH Filed sept. 22, 1919 2 sheets-sheet 1 jm Mnfw May 5, 14925.

1,536,295 C. L. HOPKlNS ET AL v ELECTRICAL SWITCH Filed sept. 22, 1919 2 sheets-sheet 2 77 5J W a 36 Patented May 5, 1925.

UNITED STATES PATENT OFFICE.

CHARLES L. HOPKINS, OF RIVER FOREST, AND WALTER F. IIINKLE, 0F CHICAGO, ILLINOIS, ASSIGNORS TO BENJAMIN ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ELECTRICAL SWITCH.

Application led September 22, 1919. Serial No. 325,447.

T0 @ZZ whom alt may concern:

Be it known that we, CHARLES L. HOPKINS, a citizen ot' the United States, residing at River Forest, in the county of Cook and State of Illinois, and WALTER F. HINKLE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Electrical Switches, of which the following is a full, clear, concise, and exact description, reference being lhad to the accompanying drawings, torming a part of this specication.

Our invention relates to electrical switches.

Cne of the objects ot' our invention is to provide an improved construction in the type of switch shown in the application ot C. L. Hopkins, Serial No. 881,624, tiled Cd tober 18, 1919. In this application also is shown a switch in which two breaks are made in the circuit substantially simultaneously, thereby dividing and decreasing the arcing effect, and consequently lessening the danger of injury to the switch and other undesirable effects.

A further object oit' our invention is to provide an electric switch for use in a receptacle, which will be cheap to manufacture, simple in construction and durable and eiicient in use.

Further objects will appear trom the detailed description to Afollow and from the appended claims.

In the drawings, in which an embodiment ot our invention is shown,

Fig. 1 is a plan view ot a pull switch socket einbodying our invention;

Fig. 2 is a section substantially on the line 2 2 of Fig. 1;

Fig. 3 is a section substantially on the line 3-3 of Fig. 1;

Fig. 4: is a section substantially on the line 4-11 of Fig. 2;

Fig. 5 is a section substantially on the line 5 5 of Fig. 1, looking in the direction ot the arrows;

Fig. 6 is a section substantially on the line 6-6 of Fig. 1, looking in the direction of the arrows;

Fig. 7 is an exploded View showing de,- tails of the switch construction; and

Fig. 8 is a detail perspective view showing' an electrical connecting member.

In order to give a general idea of the construction, it is here stated that our invention is here shown embodied in a pull switch socket, having shell and lcenter contacts 1() and 11 respectively, for engagement with an insertible 'device of the Edison type, and having wiring terminals 12 and 13, for connection with a pair of feed wires (one of the wiring terminals 12 being connected directly with the threaded shell contact), a pull switch, having two rotatably mounted switch contacts 14 and 15, (insulated from each other in the oft position of the switch, one oit' these rotatable contacts 14: being electrically connected with the center contact, and the other rotatable contact 15 being electrically connected with the wiring terminal 13) and a relatively stationary electrical conducting member 16 having a pair of contact lingers 17 and 18, with which the two rotatable contacts 14 and 15 respectively make and break contact in their movement, whereby as the movable contacts are rotated, the circuit from the wiring terminal 13 to the center contact 11 is broken at two points, substantially simultaneously, thereby dividing and 'decreasing the arcing eiifect, and consequently lessening the danger of injury to the switch.

The receptacle contacts, switch mechanism and wiring terminals are all mounted on an insulating base 19, and the insulating base and parts carried thereby are housed in a sheet metal casing 20, having a sheet metal cap 21, which canbe removed for wiring, repair, etc. The usual lining 22 ot' insulating material, such as fibre or the like, is provided between the shell contact 10 and the casing 2O and a cover 23 ot' suitable insulating material, as libre, is provided above the insulating base. 19, to prevent short circuiting of the live parts carried by the insulating base.

The wiring terminal 12 is Velectrically connected with the threaded shell contact 10, by means ot' a screw 24, (Figs. 1 and 4), the head oi' which engages the flange 25 of the threaded shell, 'and the upper end of which is threaded into the wiring terminal 12. The wiring terminal 13 is secured on the insulating base 19 by means of a screw 2G. The wiring terminals 12 and 13 are provided with the usual binding screws 27.

Cil

tween these parts.

The pull switch mechanism comprises (in addition to the twol separated rotatably mounted contacts 14 and 15 and the connecting member 16, previously referred to) a pair of rotatably mounted ratchet-shaped contact carriers 28 and 29 of insulating material, to which the contacts 14 and 15 respectively are secured, (and which, with these contacts, forms a commutator member), an oscillatable operating member or switch lever 30, which is operated to impart movement to the contact carriers 28 and 29 and the contacts carried thereby, a ratchet mechanism 31, for changing` the oscillating movement of the switch lever 39 lto a stepby-step movement in the contact-carriers 28 and 29, a pull chain 32 for operating the switch lever 30, and a coil torsion spring 33 for returning the switch lever 30 after it has been operated by the pull clrain The contact-carriers 28 and 29 are both secured to a. shaft 34of conducting material. For preventing relative rotation between the commutatore and the shaft on which they are mounted, portions of the sha-ft are pinched or flattened at 35 to provide lugs for engagement with notches 36 formed in the contact carriers 28 and 29. One end of the shaft 34 is rotatably mounted in a bracket 36, which bracket 36a is secured to the insulating base 19 by means of a screw 37 (Figs. 1 and 7) which screw also serves to electrically connect the bracket 36 and center contact 11, and to hold the center contact in place on ythe insulating base 19. The contact 14 is held in place on the contact-carrier 28 land also electrically connected with the bracket 36a by means of an inwardly extending arm 38 (Figs. 1 and 7 which is provided with an opening 39, through which the switch shaft 34 extends. A lug 40 (Fig. 7) is struck up from the material of the arm 38, and engages a recess 41 in the contact-carrier 28 to prevent relative movement between the contact 14 and contact-carrier 28. The parts when assembled are so .located that the bearing portion 42 of the bracket 36d exerts a yielding spring pressure against the inwardly extending arm 38, to insure good contact be- Tlie rotary contact 14 is thus always electrically connected with the center contact 11 through the arm 38, spring bracket 36 and the screw 37, as clearly appears from Fig. 7. The other end of the shaft 34 is mounted in a bracket portion 43 (Figs. 1 and 7) formedintegral with the wiring termiiral 13 (the shaft 34, however, being insulated fromthis bracket portion 43 by means of a` bushing 4 4 of insulating material). The contact 15 is heldin place on the contact-carrier 29 and is also electrically connected with the bracket portion 43, by means of an inwardly extending arm 45. having an opening 46 through which the bushing 44 and shaft 34 extend. A lug 47 is struck up from the arm 45 for engagement with a recess 48 formed in the contact carrier 29, whereby relative rotation between the contact and carrier is prevented. The rotatable contact 15 is thus always in electrical connection with the wiring terminal 13 through the arm 45, and bracket portion 43. The larm is, however, insulated from the shaft 34 by means of the insulating bushing 44.

The built-up switch lever or operating member 30 comprises a central spider-like member 49 (Fig. 7) having an opening 49, through which the supporting shaft 34 extends, three discs 50, 51 and 52, which are slipped over the legs of the spider 49, and a spacer sleeve 53 which separates the dises 51 and 52 and which is also slipped over the spider. These discs 50, 51 and 52 are formed of suitable insulating material, such as sheets of fibre, and the sleeve 53 is also formed of insulating mlaterial. The assembled construction comprises a sort of drum or chainrail on which-a portion of the pull chain 32 is wound. The spider 49 is also provided with ratchet teeth 54 for engagement with ratchet depressions 55 (Fig. 6) for-med in the contact carrier 28. These ratchet depressions are formed in the side face of the carrier 28 and slope inwardly from the face of the carrier, and terminate in shoulder portions against which the ends of ratchet members 54 engage.

The spider 49 and the rotatable contacts 14 and 15 may be suitable sheet metal stampings. The pull chain 32 is secured to the switch lever 30 by means of a bifurcated hook member 56 (Figs. 3 and 7) having laterally extending lugs or ears 57 which engage openings 58 and 59 respectively in the fibre discs 51 and 52 when the parts are in assembled position.

The legs of the spider are provided with outwardly projecting portions or lugs 60 that hold the insulating discs 50, 51 and 52 and the sleeve 53 in assembled position on the spider. In assembling the switch lever, the legs of the spider are bent inwardly enoughto permit the discs 50 and 51, the sleeve 53 and the disc 52 to be slipped over the outwardly extending lug 60. The ears 57 of the hook member 56 are inserted in the openings 58 and 59 respectively, before the discs 51 and 52 are moved up snugly against the ends of the sleeve 53. The discs and sleeve are prevented from slipping olf the spider at one end by their engage# ment with the lugs 60, and are prevented from slipping oif at the other end by the lugs 61 which extend outwardly from the spider. In order to position the discs 50. 51 and 52 on the spider 49, and prevent rela; tive rotation therebetween, each of these discs is provided with a number of recesses llo 63, extending from its central opening, these recesses 63 being pro-vided to receive the legs of the spider when the parts are in assembled position. The chain 32 is secured to the hoolr member 56 by engaging one of the balls in the hook portion, the shank which connects the balls lying in a space between the two hook members. The discs 50, 51 and 52 and the sleeve 53 fully insulate the pull chain 32 from the spider 49, (the disc 50 serving to cover up the end of the projection 57, which would -otherwise be exposed). The switch lever 30 is supported atvone end directly by the shaft 34 (which extends through the opening 49 of the spider) and is supported at the other end by a bearing member (Figs. 2 and 7) this member 65 having a. cylindrical portion 651 which fits inside the legs of the spider 49, and thus forms a bearing for the spider.

One end of the coil torsion spring is secured to the spider as indicated at 66 in Fig. 5. The other end of the spring is secured in a recess 67 in the insulating base 19, the lnember 65 being provided with a slot 68 to provide for the passage of the end of the spring therethrough.

As previously described, the rotatable contact 14 is always in electrical connection with the center contact, and the rotatable contact 15 is always in electrical connection with the wiring terminal. In the oli' position of the switch, these two rotatable contacts 14 and 15 are insulated from each other, but in the on position of the switch they are electrically connected with each other through the connecting member 16. The circuit from the wiring terminal 28 to the center contact is thus made and broken at two points simultaneously by moving the rotatable contacts 14 and 15 into and out of contact with respect to the connecting member 16. This connecting member 16 (Figs. 1, 3, 6 and 8) comprises, in addition to the spring' contact lingers 17 and 18 previously referred to, a base porti-on 69 secured to the insulating base 19 by means of a rivet or eyelet 70, the contact finger 17 being located so that the contact 14 can be moved into and out of contact with respect thereto, and the contact linger 18 being located so that the contact 15 can be moved into and out of contact with respect thereto by rotating the carriers 28 and 29.

As shown in Figs. 3 and 6, the contact carriers are ratchet-shaped, each having a spiral portion on which the contact rests, and each also having a spiral portion on which the spring contact finger 17 or 18 rests, when it is not in engagement with the contact.

When the contact carriers are rotated by means of the pull chain 32, from the position shown in Figs. 3 and 6, the contact iingers 17 and 18 ride upon the spiral surfaces of the insulating carriers and finally snap off from these spiral portions fdown into contact with the spiral contacts 14 and 15. During the next 180 degrees of movement the spring contact lingers 17 and 18 ride along the spiral contacts 14 and 15 and inally snap down oli from the ends of the spiral contacts onto the spiral insulating portions.

The operation of the switch has been outlined in connection with the description ot the construction. When the switch is in on position, that is, when the spring fingers 17 and 18 are in contact with the rotatable contacts 14 and 15, the circuit is 'from the wiring terminal 13 through the bracket port-ion 43, arm 45, curved portion ot the contact 15, spring iinger 18, base portion 69, spring lingers 17, curved portion of the contact 14, arm 38, bracket 36, and screw 37 to the center contact 11, thence to whatever translating device is inserted in the receptacle to the shell contact 10, and through the screw 24 to the wiring terminal 12.

Assuming that the parts are in a position corresponding to that shown in Figs. 3 and 6, in which the switch is in ofi posi.- tion, the spring contact lingers 17 and 18 being out of contact with the contacts 14 and 15, and resting on the spiral portions of the insulating carrier, if it is desired to move the switch to on position, the chain 32 is pulled down until the projections 71 on the discs 50 and 51 engage an abutment 72 on the insulating base 19. This moves the lever through 180 degrees and also moves the contact carriers 28 and 29 through 180 degrees through the intermediary of the ratchet mechanism 31. During this movement of 18() degrees, the spring Contact fingers 17 and 18 ride upon the spiral portions 73 of the contact carriers, and at the end of the movement snap down simultaneously into contact with the contacts 14 and 15 respectively. This simultaneously makes a connection at two points, and completes the circuit between the wiring terminal 13 and the center contact. The pull chain 32 is then released, and the coil torsion spring 33 returns the switch lever 30 and pull chain 32 to their original positions, the contact carriers 28 and 29, however, remaining stationary during this return movement of the switch lever 30, the ratchet mechanism 31 permitting this return movement of t'he switch lever 30 without a lcorresponding movement of the can.. riers. Moreover, the spring fingers 17 and 18 would resist the return movement of the carriers 28 and 29, as the ends of these spring fingers would engage the shoulders at the ends of the spiral portions 73 and would prevent a return movement of the carriers.

The return movement of the switch lever 30 under the action ot the torsion spring 33 is limited by the engagement of the proj ection 71 with a suitably located abutment Tet ou the insulating base 19.

f it is desired to move the switch from on to olf position, the pull chain 32 is moved down again to move the lever 30 through an angle of degrees. The pull chain is then released, and the torsion spring 33 again throws the switch lever back to its original position. During this movement of the switch lever 30 the contact carriers 28 and 29 are advanced through another movement of 180 degrees, the carriers, however, remaining stationary during the re turn movement of the switch levers. During the forward movement of 180 degrees of the carriers the spring contact fingers 17 and 18 ride upon the spiral contact portions of the contacts 1li and 15 respectively, and at the end of the movement snap oli' from the ends of the spiral portions of the contacts, thus making a quick simultaneous double break in the circuit from the wiring terminal 13 to the center contact thus breaking the arc at two points and greatly lessening the chance of injury to the contacts and other undesirable effects.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A switch mechanism comprising two spaced contact carriers of insulating material, mounted to rotate about a common axis in different parallel planes, two contacts, one carried by each carrier, a pair of stationary contacts, one for each rotatable contact with respect to which said rotat able contacts make and break connection in the rotation of said carriers, means for actuating said carriers comprising a drum oseillatable about the same axis as said carriers, a pull member mounted on said drum, and a coil torsion spring coaxial with said carriers and located inside said drum for returning said drum.

2. A switch mechanism comprising a rotatable contact carrier and contact, a pull member for operating said contact carrier,

a chain rail of insulating material to which said pull member is secured, and two telescopic members, to one of which said chain rail is secured and one of which forms a bearing for the other, and a spring for returning said chain rail housed between said telescoping members.

3. A switch mechanism comprising a contact carrier of insulating material, a contact carried by said contact carrier, and having an arm overlying the side face of said carrier, and means for rotatably supporting said carrier, comprising a leaf spring support, yie'ldingly bearing against said arm,l said arm and spring support being of conducting material and forming part of the electrical circuit.

4t. A switch mechanism comprising a pair of insulating cam wheels arranged to rotate together in differentparallel planes, each of said cam wheels having two high points and two drops and having also a curved contact plate extending around substantially 180 degrees thereof, a pair of interconnected stationary contacts arranged to drop ottl said contact plates simultaneously, and a ratchet device located between said cam wheels for advancing the latter with a. step by step movement.

5. In an electric switch, the combination of an insulating base, a shaft, bearings for said shaft carried by said base, a pair of insulating members carried by said shaft, a contact carried by each of said insulating members, each of said contacts having a part for electrical Contact with one of said bearings, means mounted on said base for bridging said contacts, whereby said bearings are electrically interconnected, said bridging means being arranged to break the circuit at both of said contacts simultaneously, and ratchet means for turning said shaft, said means comprising a member ar ranged to oscillate upon said shaft.

In witness whereof, we have hereunto sub scribed our names.

CHARLES L. HOPKINS. VALTER F. HINKLE.

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